Bernie used several bricks yesterday when he started to build the chimney. Today he added $32$ more bricks. Now, the chimney has a total of $99$ bricks. How many bricks did Bernie use yesterday?
Solution: To find how many bricks Bernie used yesterday, we start with the $99}$ bricks the chimney has now and subtract the ${32}$ bricks added today. $99$ $32$ $?$ Total bricks Bricks added Bricks to start $99}-{32} = {\Box}$ Let's subtract to find how many bricks were on the chimney when he started. $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $99}-{32}= {67}$ Bernie used ${67}$ bricks yesterday.